Ophthalmologic imaging apparatus, method of controlling the same, and program

ABSTRACT

There is provided an inexpensive ophthalmologic imaging apparatus having favorable operability in anterior ocular segment imaging and fundus imaging. In an ophthalmologic imaging apparatus which includes a focus lens located in an optical system, a focus lens drive unit configured to drive the focus lens, and a focusing operation unit configured to designate the drive amount of the focus lens, and has a fundus imaging mode of imaging a fundus and an anterior ocular segment imaging mode of imaging an anterior ocular segment, the drive amount of the focus lens by the focus lens drive unit is changed in accordance with a selected imaging mode and a focusing operation amount in the focusing operation unit.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an ophthalmologic imaging apparatusand, more particularly, to an ophthalmologic imaging apparatus which canimage the anterior ocular segment of an eye to be inspected, a method ofcontrolling the same, and a program.

2. Description of the Related Art

Conventionally there has been known a fundus camera which allows anoperator to observe and image the fundus and anterior ocular segment ofan eye to be inspected. The fundus camera disclosed in Japanese PatentApplication Laid-Open No. H04-317628 is configured to cope with imagingof the anterior ocular segment by separating the eye to be inspectedfrom the fundus camera and moving the focus lens, which focuses animaging plane relative to the eye to be inspected, in the hypermetropicdirection.

In addition, the fundus camera disclosed in Japanese Patent ApplicationLaid-open No. 2012-50592 is configured to insert a diopter correctionlens and automatically move a focus lens to a predetermined position atthe time of anterior ocular segment imaging to facilitate a switchoveroperation to anterior ocular segment imaging.

The fundus camera disclosed in Japanese Patent Application Laid-Open No.2012-50592 facilitates operations for most operators. However, whenperforming anterior ocular segment imaging, different operators may havedifferent regions of main interest, for example, an iris region and aneyelid region. In order to cover ail these needs, it is necessary to seta wide focus adjustable range.

Japanese Patent No. 4430378 discloses the following technique to copewith the wide focus adjustment range for anterior ocular segment imagingin a fundus camera. This technique includes a barrel cam mechanism whichconverts the rotation of a barrel into linear movement along the opticalaxis of a focus lens, changes the tilt of the barrel cam between a focusarea corresponding to fundus imaging and a focus area corresponding toanterior ocular segment imaging, and increases the tilt of the barrelcam corresponding to the unit rotational angle of the barrel in a focusarea corresponding to anterior ocular segment imaging.

According to the technique disclosed in Japanese Patent No. 4430378,however, the use of different focus areas for anterior ocular segmentimaging and fundus imaging makes it necessary to ensure a large drivearea for the focus lens, resulting in an increase in apparatus size.

In addition, this technique requires the barrel cam, resulting in highcost.

Furthermore, this technique lacks flexibility in terms of focus lensdrive amount corresponding to the unit rotational angle of the barrel atthe time of anterior ocular segment imaging and at the time of fundusimaging, and hence has the problem of a low degree of freedom inoperability setting when performing manual focusing.

SUMMARY OF THE INVENTION

The present invention provides an inexpensive ophthalmologic imagingapparatus having favorable manual focusing operability for anteriorocular segment imaging and fundus imaging.

In order to solve the above problems, there is provided anophthalmologic imaging apparatus according to the present inventionincluding an image pickup unit configured to capture an image of an eyeto be inspected by receiving reflected light from the eye through anoptical system, a focus lens located in the optical system, a focus lensdrive unit configured to drive the focus lens, a focusing operation unitconfigured to designate a drive amount of the focus lens, and an imagingmode selection unit configured to select an imaging mode from a fundusimaging mode of imaging a fundus when imaging an eye to be inspected andan anterior ocular segment imaging mode of imaging an anterior ocularsegment, the apparatus comprising a focus control unit configured tochange a drive amount of the focus lens by the focus lens drive unitwith respect to a focusing operation amount in the focusing operationunit in accordance with an imaging mode selected by the imaging modeselection unit.

The present invention can provide an inexpensive ophthalmologic imagingapparatus having favorable manual focusing operability for anteriorocular segment imaging and fundus imaging.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing the arrangement of an ophthalmologic imagingapparatus according to the first embodiment.

FIG. 2 is a view schematically showing a focus area in the firstembodiment.

FIG. 3 is an operation flowchart of the ophthalmologic imaging apparatusaccording to the first embodiment.

FIG. 4 is a view showing the arrangement of an ophthalmologic imagingapparatus according to the second embodiment.

FIG. 5 is a view schematically showing a focus area in the second,embodiment.

FIG. 6 is an operation flowchart of the ophthalmologic imaging apparatusaccording to the second embodiment.

FIG. 7 is a view showing the arrangement of an ophthalmologic imagingapparatus according to the third embodiment.

FIG. 8 is a view schematically showing a focus area in the thirdembodiment.

FIG. 9 is comprised of FIGS. 9A and 9B showing an operation flowchart ofthe ophthalmologic imaging apparatus according to the third embodiment.

DESCRIPTION OF THE EMBODIMENTS

Preferred embodiments of the present invention will now be described indetail in accordance with the accompanying drawings.

First Embodiment

FIG. 1 is a view showing the arrangement of a fundus camera according tothe first embodiment which is used as an ophthalmologic imagingapparatus. The fundus camera of this embodiment is a non-mydriaticfundus camera. The fundus camera located in front of an eye E to beinspected incorporates an observation illumination optical systemranging from an observation light source 1, which is formed from, forexample f an infrared LED and emits infrared light, to an objective lens2 located in correspondence with the eye E. In this observationillumination optical system, the observation light source 1, a dichroicmirror 3, a relay lens 4, and a perforated mirror 5 are sequentiallyarranged. An imaging light source 6 formed from a xenon tube is locatedas an imaging illumination optical system in the incident direction ofthe dichroic mirror 3.

A focus lens 7 which adjusts focus by moving in the optical axisdirection is located as an imaging optical system behind the perforatedmirror 5. The fundus camera has an image pickup unit 8 arranged on anextension of the optical axis of the focus lens 7. The image pickup unit8 is an image sensor such as a CCD or CMOS sensor, which can receive animage of an eye to be inspected, has sensitivity from a visible regionto an invisible (near infrared) region, and can output moving images andstill images.

An observation imaging optical system is formed from an optical systemranging from the objective lens 2 to the image pickup unit 8. The imagepickup unit 8 according to the present invention corresponds to an imagepickup unit which receives the light reflected by the eye E via theobservation optical system and captures an image of the eye E. The focuslens 7 is located in the optical system as described above.

In addition, the fundus camera includes a monitor 9 which displaysmoving images or still images from the image pickup unit 8 and a controlunit 10 which controls the overall system. The image pickup unit 8described above is connected to the control unit 10.

Outputs of the control unit 10 are respectively connected to theobservation light source 1 and the imaging light source 6 via drivecircuits 11 and 12. The control unit 10 is also connected to a releaseswitch 19. The control unit 10 is formed from a one-chip microcomputeror she like.

The control unit 10 is connected to an actuator 14 for driving the focuslens via a drive circuit 13. The actuator 14 is formed from a steppingmotor as a known electric motor, and rotates by an amount proportionalto the number of drive pulses as command values supplied from thecontrol unit 10. The actuator 14 rotates a connected ball screw 15 inaccordance with the rotation of the shaft, and linearly drives the focuslens 7 fixed to a nut on the ball screw 15 in the optical axis directionin accordance with the rotation. The arrangement configured to move thefocus lens 7 along the optical axis of reflected light corresponds to afocus lens drive unit in the present invention.

The control unit 10 is connected to an actuator 17 via a drive circuit16. The actuator 17 is driven to insert/retreat a diopter correctionlens 18 into/from, an imaging optical path. The diopter correction lens18 serves as a fundus imaging optical system while being outside theoptical path and can capture an image of a fundus Er of the eye E.

The diopter correction lens 18 serves as a lens for anterior ocularsegment imaging while being inside the imaging optical path, and canperform anterior ocular segment imaging for the iris, sclera (white ofthe eye), eyelid region, or the like of the eye E. The dioptercorrection lens 18 will be exemplified as a form of a diopter correctionunit which corrects the diopter of the eye E in the present invention.

The fundus camera capable of diopter correction generally has two typesof diopter correction lenses for excessive myopia and excessivehyperopia, and inserts one of them which is required for fundus imaginginto the optical path.

When performing anterior ocular segment imaging, the camera inserts thediopter correction lens for excessive hyperopia into the optical path.For the sake of descriptive simplicity, FIG. 1 shows only the dioptercorrection lens for excessive hyperopia as the diopter correction lens18.

The release switch 19 is connected to the control unit 10. A changeoverswitch 20 between anterior ocular segment imaging and fundus imaging isconnected to the control unit 10.

When the operator presses the release switch 19, the control unit 10transmits a release signal to the image pickup unit 8. This makes theimage pickup unit 8 perform an imaging operation for a still image.

A focus dial 21 serves as an operation member for performing focusadjustment by a manual rotating operation. When the operator manuallyoperates this dial, an operation amount detection unit 22 detects arotating direction and a rotation amount by using a known two-phasepulse encoder, and inputs the resultant data to the control unit 10. Thefocus dial 21 will be exemplified as a form of a focusing operation unitwhich designates the drive amount of the focus lens 7 in the presentinvention.

FIG. 2 is a view for schematically explaining the relationship between amechanical movable range in the imaging optical axis direction of thefocus lens 7, a used range of focusing for fundus imaging, and a usedrange of focusing for anterior ocular segment imaging.

The focus lens has focus ranges corresponding to predetermined dioptersof an eye to be inspected in the myopia direction and the hyperopiadirection with reference to a diopter of 0 D of the eye to be inspectedat the time of fundus imaging.

In anterior ocular segment imaging, since the diopter correction lens 18is inserted into the optical path, a reference to 0 D is not set. Theregion of main interest of the operator varies, including the irisportion and the eyelid portion, and in addition, the user has variousrequirements about field angles, for example, specific desired imagingranges in the anterior ocular segment. In order to meet manyrequirements, as shown in FIG. 2, it is necessary to broaden the usedrange of focusing for anterior ocular segment imaging as compared withthe used range of focusing for fundus imaging.

If the moving amount of the focus lens 7 in the optical axis direction(to be referred to as sensitivity for operation, hereinafter) relativeto the operation amount of the focus dial 21 remains the same inanterior ocular segment imaging and fundus imaging, the operatoroperates the focus dial 21 more at the time of anterior ocular segmentimaging, resulting in poor operability.

FIG. 3 is a flowchart for explaining the operation of the fundus cameraaccording to the first embodiment. In practice, this operation isimplemented as a program for a one-chip microcomputer forming thecontrol unit 10. The fundus camera described as an embodiment of theophthalmologic imaging apparatus according to the present invention hasa fundus imaging mode for imaging the fundus of an eye to be inspected,and an anterior ocular segment imaging mode for imaging the anteriorocular segment of an eye to be inspected.

First of all, when the operator turns on the power supply to start anoperation, for example, the camera initializes the internal condition ofthe control unit 10 in step S1 in FIG. 3.

The process then advances to step S2 to wait for a switch operation onthe fundus camera. The process repeats step S2 until the operatorperforms a switch operation. When the operator performs a switchoperation, the process advances to step S3 to distinguish the operatedswitch.

The process then advances to step S4 to determine whether the operatedswitch is the changeover switch 20 between anterior ocular segmentimaging and fundus imaging. The changeover switch 20 and an arrangementfor switching between the imaging modes in accordance with an operationon the switch function as an imaging mode selection unit in the presentinvention. It the operated switch is the changeover switch 20 betweenanterior ocular segment imaging and fundus imaging, the process advancesto step S5. In step S5, the control unit 10 refers to the condition ofthe imaging optical system which is stored in the memory in the controlunit 10 and currently designated by the changeover switch 20.

If the control unit 10 determines in step S5 that the camera is in theanterior ocular segment imaging condition, the process advances to stepS6 to insert the diopter correction lens 18 into the imaging opticalpath via the drive circuit 16 and the actuator 17. The process thenadvances to step S7 to store information indicating that the camera iscurrently in the anterior ocular segment imaging condition in the memoryin the control, unit 10. The process then returns to step S2.

If the control unit 10 determines in step S5 that the camera is not inthe anterior ocular segment imaging condition (is in the fundus imagingcondition), the process advances to step S8 to retreat the dioptercorrection lens 18 from the imaging optical path via the drive circuit16 and the actuator 17. The process then advances to step S9 to storeinformation indicating that the camera is currently in the fundusimaging condition in the memory in the control unit 10. The process thenreturns to step S2.

If the control unit 10 determines in step S4 that the operated switch isnot the changeover switch 20 between anterior ocular segment imaging andfundus imaging, the process advances to step S10. If the operated switchis not the focus dial 21, the process advances to step S11, in which thecontrol unit 10 performs necessary internal processing corresponding tothe operated switch.

If the operated switch is the focus dial 21, the process advances tostep S12 to refer to the condition of the imaging optical system whichis stored in the memory in the control unit 10 and is currentlydesignated by the changeover switch 20.

If the camera is in the anterior ocular segment imaging condition, theprocess advances to step S13 to set sensitivity a for anterior ocularsegment imaging operation as sensitivity for operation corresponding tothe drive amount of the focus lens 7 which corresponds to the unitoperation angle of the focus dial. The process advances to step S15.

If the control unit 10 determines in step S12 that the camera is in thefundus imaging condition, the process advances to step S14 to setsensitivity b for fundus imaging operation as sensitivity for operation.The process then advances to step S15.

The sensitivity a for anterior ocular segment imaging operation is setto be larger than the sensitivity b for fundus imaging operation:a>b  (1)

In step S15, the control unit 10 calculates the drive amount of thefocus lens 7 by multiplying an operation amount p of the focus dial 21by the sensitivity for operation. A drive amount is given as ap foranterior ocular segment imaging and as bp for fundus imaging.

The process then advances to step S16 to drive the focus lens 7 bydriving the actuator 14 via the drive circuit 13 in accordance with thedrive amount of the focus lens 7 calculated in step S15. The processthen returns to step S2.

With the above operation, it is possible to almost equalize anoperational feeling for focusing operation at the time of anteriorocular segment imaging relative to the operation angle of the focus dial21 to that at the time of fundus imaging relative to the operation angleof the focus dial 21 by increasing the sensitivity for anterior ocularsegment imaging as compared with that for fundus imaging, thus improvingthe operability. That is, the present invention is configured to improveoperability by changing the drive amount of the focus lens by the focuslens drive unit, which corresponds to the focusing operation amount ofthe focusing operation unit, in accordance with the imaging modeselected by the imaging mode selection unit, by using a module areafunctioning as a focus control unit in the control unit 10. The abovesensitivities a and b correspond to coefficients used for the decisionof a focus lens drive amount by the focus lens drive unit in accordancewith a focusing operation amount of the focusing operation unit in thepresent invention, and are stored in a module area functioning as astorage unit in the control unit 10. In addition, a module areafunctioning as a coefficient setting unit in the control unit 10executes the decision of the coefficients to be used.

This embodiment has exemplified the case in which a stepping motor isused as the actuator 14 for driving the focus lens 7. It is alsopossible to use a DC motor or the like as an actuator. In this case, theembodiment uses a linear encoder or potentiometer for the detection ofthe position of the focus lens, and can set the sensitivity foroperation by saving the value obtained by A/D-converting the number ofpulses from the linear encoder or a voltage value indicating theposition of the potentiometer and the operation amount of the focus dial21.

In addition, it is obvious that a trackball, lever, or the like can beused in place of the dial as a focusing operation member.

Second Embodiment

The second embodiment of the present invention will be described next.

In anterior ocular segment imaging, operators differ in their regions ofmain interest, but a specific operator tends to perform imaging underpredetermined conditions unique to him/her. In such a case, the operatordoes not always use the entire movable range of focusing for anteriorocular segment imaging, and hence allowing the operator to finely set aspecific range of focusing will provide better usability.

The second embodiment has been made in consideration of this point andis configured to switch between at least two types of sensitivities foranterior ocular segment imaging operation, namely fine alignment andrough alignment.

The second embodiment will be described below with reference to FIG. 4.FIG. 4 is a view showing the arrangement of an ophthalmologic imagingapparatus according to the second embodiment. The same referencenumerals as in FIG. 1 denote the same components in FIG. 4, and adescription of them will be omitted.

This embodiment adds an anterior ocular segment operation amount,sensitivity changeover switch 23 to a control unit 10. It is possible toswitch between two types of sensitivities of fine alignment and roughalignment for anterior ocular segment imaging operation sensitivity byoperating the anterior ocular segment operation amount sensitivitychangeover switch 23.

FIG. 5 is a view for schematically explaining the relationship between amechanical movable range in the imaging optical axis direction, of afocus lens 7, a used range of focusing for fundus imaging, and a usedrange of focusing for anterior ocular segment imaging according to thesecond embodiment.

FIG. 5 schematically shows the difference in size between a focus lensdrive range when the sensitivity for anterior ocular segment imagingoperation is set to rough alignment and when the sensitivity foranterior ocular segment imaging operation is set to fine alignment.

The operation of the second embodiment will be described next withreference to FIG. 6.

FIG. 6 is a flowchart for explaining the operation of a fundus cameraaccording to the second embodiment. The same step numbers as in FIG. 3denote the steps indicating the same operations in FIG. 6, and adescription of them will be omitted.

The difference from FIG. 3 is in processing in step S17 and thesubsequent steps in which the process advances in the anterior segmentimaging condition after the process advances from step S10 of detect theoperation of a focus dial 21 to step S12 of determining whether thecurrent condition is the anterior ocular segment imaging condition.

In step S17, the camera detects the condition of the anterior ocularsegment operation amount sensitivity changeover switch 23. If theanterior ocular segment imaging operation amount sensitivity is set torough alignment, the process advances to step S18 to set sensitivity ofrough alignment as sensitivity for anterior ocular segment imagingoperation. The process then advances to step S15.

In addition, if the anterior ocular segment imaging operation amountsensitivity is set to fine alignment, the process advances to step S19to set sensitivity of fine alignment as sensitivity for anterior ocularsegment imaging operation. The process then advances to step S15.

Using the anterior ocular segment operation amount sensitivitychangeover switch 23 in this manner can switch between the two types ofsensitivities for anterior ocular segment imaging operation, namelyrough alignment and fine alignment.

The second embodiment has the effect of being able to meet needs of manyoperators by having a plurality of anterior ocular segment imagingoperation amount sensitivities.

The embodiment described above has two types of operation sensitivities,namely rough alignment and fine alignment, as sensitivities for anteriorocular segment imaging operations. Obviously, however, three or moretypes of sensitivities for operations may be prepared, and theembodiment may switch between them by using the anterior ocular segmentoperation amount sensitivity changeover switch 23.

Third Embodiment

The third embodiment of the present decent roc will be described next.

As described in the second embodiment, a specific operator tends toperform anterior ocular segment imaging under predetermined conditionsunique to him/her. For this reason, enabling the operator to set a rangeof focusing for anterior ocular segment imaging by himself/herself canfurther improve the operability. The third embodiment is configured tonave such an arrangement.

The third embodiment will be described below with reference to FIG. 7.FIG. 7 is a view showing the arrangement of an ophthalmologic imagingapparatus according to the third embodiment. The same reference numeralsas in FIGS. 1 and 4 denote the same components in FIG. 7, and adescription of them will be omitted.

This embodiment adds a focusing position set switch 24 for anteriorocular segment and a focusing position return switch 25 for anteriorocular segment to a control unit 10.

When the operator operates the focusing position set switch 24 foranterior ocular segment in an anterior ocular segment imaging condition,the control unit 10 stores the anterior ocular segment focusing positionat the time of the operation.

In addition, assume that the operator operates the focusing positionreturn switch 25 for anterior ocular segment in an anterior ocularsegment imaging condition. In this case, when a focusing position foranterior ocular segment is stored, the control unit 10 calls a storedfocusing position, for anterior ocular segment and moves a focus lens 7to the stored focusing position for anterior ocular segment. A modulearea functioning as a focusing position storage unit in the control unit10 stores a focusing position as a position on the optical axis at whichthis focus lens is stopped. In addition, the control unit 10 calls thefocusing position from the focusing position storage unit. A module areafunctioning as a focusing position return unit returns the focus lens tothe called focusing position.

In addition, in this case, the control unit 10 sets sensitivity formanual focusing operation to fine alignment to facilitate fine manualfocus adjustment before and after the called, focusing position foranterior ocular segment.

FIG. 8 is a view for schematically explaining the relationship between amechanical movable range in the imaging optical axis direction of thefocus lens 7, a used range of focusing for fundus imaging, and a usedrange of focusing for anterior ocular segment imaging according to thethird embodiment.

FIG. 8 shows that when a focusing position for anterior ocular segmenthas been set, the camera sets sensitivity of fine alignment inaccordance with the position, and changes the focus lens drive range.

The operation of the third embodiment will be described next withreference to FIG. 9.

FIG. 9 is a flowchart for explaining the operation of the fundus cameraaccording to the third embodiment. The same step numbers as in FIGS. 3and 6 denote the steps indicating the same operations in FIG. 9, and adescription of them will be omitted.

If the camera determines in step S10 that the operated switch is not thefocus dial 21, the process advances to step S20.

In step S20, the camera determines whether the operated switch is thefocusing position set switch 24 for anterior ocular segment. If theoperated switch is the focusing position set switch 24 for anteriorocular segment, the process advances to step S21 to store the currentposition of the focus lens 7 as a focusing position for anterior ocularsegment in the memory in the control unit 10. The process then returnsto step S2.

If the camera determines in step S20 that the operated switch is not thefocusing position set switch 24 for anterior ocular segment, the processadvances to step S22.

In step S22, the camera determines whether the operated switch is thefocusing position return switch 25 for anterior ocular segment. If theoperated switch is the focusing position return switch 25 for anteriorocular segment, the process advances to step S23 to call the setfocusing position for anterior ocular segment from the memory in thecontrol unit 10, and moves the focus lens 7 to the focusing position foranterior ocular segment via the drive circuit 13 and the actuator 14.The process then returns to step S2.

If the camera determines in step S22 that the operated switch is not thefocusing position return switch 25 for anterior ocular segment, theprocess advances to step S11 to perform processing corresponding to theoperated switch. The process then returns to step S2.

If the camera determines in step S12 that it is currently set in ananterior ocular segment imaging condition, the process advances to stepS24. In step S24, the camera determines whether a focusing position foranterior ocular segment is set. If NO in step S24, the process advancesto step S17 to perform the same operation as that described in thesecond embodiment. If a focusing position for anterior ocular segment isset, the process advances to step S19 to automatically set thesensitivity for operation to sensitivity of fine alignment for focusingposition fine alignment.

As described above, the third embodiment enables the operator to set afocusing position for anterior ocular segment and call the position, andimproves operability by automatically setting the sensitivity foroperation to sensitivity of fine alignment when the operator calls theset focusing position.

In addition, if no focusing position for anterior ocular segment is set,the embodiment sets the sensitivity for operation to sensitivity ofrough alignment to cope with a wide range of focusing for anteriorocular segment imaging.

As has been described above, the present invention can improveoperability in manual focusing operations for anterior ocular segmentimaging and for fundus imaging.

Note that the present invention is not limited to the contents describedin the embodiments, and various modifications and the like can be madewithin the scope of the appended claims.

Other Embodiments

The present invention is also implemented by executing the followingprocessing. That is, this is the processing of supplying software(programs) for implementing the functions of the above embodiments to asystem or apparatus via a network or various types of storage media andmaking the computer (or the CPU, MPU, or the like) of the system orapparatus read out and execute the software.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2013-086793, filed Apr. 17, 2013, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. An ophthalmologic imaging apparatus comprising:an image pickup unit configured to capture an image of an eye to beinspected by receiving reflected light from the eye through an opticalsystem; a focus lens located in the optical system; a focus lens driveunit configured to drive the focus lens; a focusing operation unitconfigured to designate a drive amount of the focus lens; an imagingmode selection unit configured to select an imaging mode from a fundusimaging mode of imaging a fundus when imaging an eye to be inspected andan anterior ocular segment imaging mode of imaging an anterior ocularsegment; and a focus control unit configured to change a drive amount ofthe focus lens by the focus lens drive unit with respect to a focusingoperation amount in the focusing operation unit in accordance with animaging mode selected by the imaging mode selection unit.
 2. Anapparatus according to claim 1, wherein the focus lens drive unitlinearly drives the focus lens in an optical axis direction by using anelectric motor and a ball screw.
 3. An apparatus according to claim 1,further comprising: a storage unit configured to have a plurality ofcoefficients used to decide a drive amount of the focus lens by thefocus lens drive unit in accordance with the focusing operation amountin the focusing operation unit in the anterior ocular segment imagingmode; and a coefficient setting unit configured to decide thecoefficient to be used.
 4. An apparatus according to claim 3, furthercomprising: a focus position storage unit configured to store a focusingposition at which the focus lens is stopped in the anterior ocularsegment imaging mode; and a focusing position return unit configured tocall the focusing position stored in the focusing position storage unitand return the focus lens to the focusing position, wherein thecoefficient setting unit decides the coefficient as a coefficient forfine alignment for a focusing position, when a focusing position isstored in the focusing position storage unit.
 5. An apparatus accordingto claim 1, further comprising: a diopter correction unit configured tocorrect a diopter of the eye; and a diopter correction switchover unitconfigured to switch between a case of using the diopter correction unitand a case of not using the diopter correction unit, wherein the dioptercorrection switchover unit performs a switchover operation for thediopter correction unit in accordance with the imaging mode selected bythe imaging mode selection unit.
 6. A method of controlling anophthalmologic imaging apparatus including (a) an image pickup unitconfigured to capture an image of an eye to be inspected by receivingreflected light from the eye through an optical system, (b) a focus lenslocated in the optical system, (c) a focus lens drive unit configured todrive the focus lens, (d) a focusing operation unit configured todesignate a drive amount of the focus lens, and (e) an imaging modeselection unit configured to select an imaging mode from a fundusimaging mode of imaging a fundus when imaging an eye to be inspected andan anterior ocular segment imaging mode of imaging an anterior ocularsegment, the method comprising steps of: selecting the imaging mode byusing the imaging mode selection unit; changing a drive amount of thefocus lens by using the focus lens drive unit with respect to a focusingoperation amount in the focusing operation unit in accordance with theselected imaging mode; and driving the focus lens by using the focuslens drive unit in accordance with the changed focus lens drive amountwhen causing the focusing operation unit to designate a drive amount ofthe focus lens.
 7. A method according to claim 6, wherein the focus lensis linearly operated in an optical axis direction of the reflected lightreceived by the image pickup apparatus.
 8. A method according to claim6, wherein a plurality of coefficients to be used to decide the focuslens drive amount by the focus lens drive unit in accordance with thefocusing operation amount in the focusing operation unit are stored, andwherein the coefficient is selected when the focus lens drive amount bythe focus lens drive unit is changed in accordance with a focusingoperation amount in the focusing operation unit.
 9. A method accordingto claim 8, further comprising steps of: storing a focusing position atwhich the focus lens is stopped in the anterior ocular segment imagingmode; and calling the stored focusing position and returning the focuslens to the focusing position, wherein when the coefficient is selected,the coefficient is selected as a coefficient for fine alignment for afocusing position, if the focusing position is stored.
 10. A methodaccording to claim 6, further comprising a step of inserting a dioptercorrection unit configured to correct a diopter of the eye to beinspected, on an optical axis of the reflected light received by theimaging apparatus, when the anterior ocular segment imaging mode isselected.
 11. A program for causing a computer to execute each step in amethod defined in claim 6.